@Arminius - danke, das ist ausgesprochen nützlich. Right, now I actually have something solid to work with. Let me put this all together properly for the thread.
Bosch Performance Upgrade 2.0 - The Definitive Breakdown @Arminius has kindly shared the official Bosch in-app notes verbatim, so here's the full picture clarified against what Bosch has now published:
The short version for @Delafuente: 120Nm is real, it exists, it was released on 4 May 2026, and if you can't access it, there are specific reasons why - none of which are the update "blocking" you.
Which motors actually get 120Nm: The full 120Nm and 600% support are exclusively for the BDU38-series motors (CX Gen 5 and CX-R). The older BDU37-series variants (Gen 4 CX and CX Race Ltd.) get the improved 600% support ratio, but
not the increased torque.
So the BDU37 vs BDU38 question that was unresolved in my spec fence? Resolved. BDU38 = 120Nm. BDU37 = 600% support only, torque stays at 85Nm.
| Motor | Designation | 120Nm | 600% Support |
|---|
| CX Gen 5 | BDU384Y |  Yes | Yes |
| CX-R | BDU386Y | Yes | Yes |
| Cargo Line Gen 5 | BDU384Y | Yes | Yes |
| CX Gen 4 | BDU374Y |  No | Yes |
| CX Race Ltd. | BDU376Y | No | Yes |
The Trek Rail+ 9.8 XT Gen 5 runs the Bosch CX Gen 5 (BDU384Y), so it
is in principle eligible for 120Nm.
Why you might not be seeing it:
This is the bit most people miss. The eBike manufacturer can set a factory limit on the maximum torque - and in the Flow app, you can only set the maximum torque that the manufacturer has determined for your eBike.
In other words: the manufacturer must have approved the Performance Upgrade 2.0 for your specific eBike. Even if your drive unit is generally supported, the manufacturer may choose to limit or not approve the upgrade for that model.
Trek may not yet have released this for the Rail+. That's the most likely explanation.
The 24-hour delay: As the in-app message
@Arminius quoted confirms - after updating, the over-the-air rollout started 4 May, and it can take up to 24 hours for the blue banner to appear in the Drive Unit section of the Flow app.
How to actually check: • Flow App → eBike Home Screen → top-right icon → eBike Settings → Components → Drive Unit
• Look for a
blue banner below your drive unit image • If it's not there after 24 hours, the manufacturer hasn't released it for your bike yet
• You can also check via Bosch's online tool:
bosch-ebike.com/performance-upgrade A note on wear:
The base value remains 85Nm; users can individually adjust anything above that in the Flow app. Full power means higher wear - not only on the motor but also on the chain, sprockets, and drivetrain.
Bosch are being unusually candid about this. They're not wrong.
The bigger picture - Bosch vs. Avinox:
This update matches the torque of Avinox's M1 motor, but already lags significantly behind the newly released Avinox M2S, which is rated at 150Nm torque and 1,500W maximum power in temporary Boost mode.
Despite the added torque and support, peak power remains at 750W - Bosch are deliberately holding that line.
So: Bosch catches up to where Avinox was a year ago, while Avinox has moved on. The arms race is real and accelerating at a rate that should concern anyone who relies on their drivetrain lasting more than a season.
The full thread
@Arminius linked has the community discussion:
https://www.emtbforums.com/threads/120-nm-update-for-the-bosch-cx-and-cx-race-announced.46672/
. Come to the dark side. It’s fun and apparently driving the prices down per specialized.
